Science 3 Marks Question

(i) The patient was not given food directly because after an operation the digestive system needs rest, and the patient may not be able to digest food properly.
(ii) Glucose provides instant energy as it is directly absorbed into the blood, helping the patient recover strength and heal faster.

(i) The condition in which a person passes watery stools is called diarrhoea.
(ii) The solution of sugar and salt in water is called Oral Rehydration Solution (ORS).
It is given to a person suffering from diarrhoea because it replaces the lost water and salts, preventing dehydration and helping in fast recovery.

(i) Hiccup is a sudden, involuntary contraction of the diaphragm muscle, followed by the quick closing of the vocal cords, producing the "hic" sound.
(ii) We get hiccups when the diaphragm gets irritated, often due to eating too fast, overeating, drinking very cold or hot water, or swallowing air.

Oral rehydration solution is the solution of sugar and salt in a particular ratio in the clean water. When a person passes out watery stools frequently, the disease is called diarrhoea. In this condition there is a loss of water and salt from the body of a person.
This is called dehydration, which may be fatal if not cured at proper time. In order to prevent dehydration, the person or patient should be given ORS. It makes up the loss of water and salts in the body and sugar provides energy which helps in the recovery of disease. It should be given to a patient suffering from diarrhoea at a regular interval.
At home the ORS can be prepared by dissolving a teaspoonful of sugar and pinch of salt in a glass of clean water. The water used for preparing ORS should be first boiled and then cooled so that all the microorganisms or harmful bacteria may be killed.

Ruminants such as cows and buffaloes swallow their food hurriedly and store it in a part of the stomach called rumen. The cellulose of the food is digested here by the action of certain bacteria, which are not present in humans. Later their partially digested food is returned to the buccal cavity of the animals in small lumps and animals chew it to complete the process of digestion. This process is called rumination.

The difference between milk teeth and permanent teeth are as follows

Milk teeth	Permanent teeth
They grow during infancy. i.e. when one is small baby.	They grow at the age of 6-8 years.
They are also called as temporary teeth because these are lost at the age of 6-8 years.	They do not fall until old age or due to some dental disease.
They can be replaced by permanent teeth.	If these teeth fall down, no new teeth arise on their place.

The various processes that are involved in the nutrition are as follows
(i) Ingestion The process by which food is taken into the body of an organism is called ingestion.
(ii) Digestion The process by which the food containing large insoluble substances is broken down into small water soluble substances is called digestion. There are two methods of digesting food, i.e., physical method (including chewing and grinding of food in mouth) and chemical method (addition of digestive juices to the food by the body itself).
(iii) Absorption The process by which the digested food passes through the intestinal wall into blood stream is called absorption.
(iv) Assimilation The process by which the absorbed food is taken in by body cells and used for energy, growth and repair is called assimilation.
(v) Egestion The process by which the undigested food material is removed from the body is called egestion.

The digestive system is composed of following parts

The mode of nutrition in the given organisms is :
(i) Butterfly - Sucking
(ii) Snail - Scraping
(iii) Frog - Swallowing
(iv) Snake - Swallowing
(v) Ant - Chewing